Question

What is the momentum of photon of energy 3 MeV in $kgm{s}^{-1}$?

• A. $9\times {10}^{-21}$
• B. $1.6\times {10}^{-21}$
• C. $3\times {10}^{-28}$
• D. $9\times {10}^{-28}$

Answer 1

The correct option is B $1.6\times {10}^{-21}$

$p=\frac{E}{C}=\frac{3\times {10}^6\times 1.6\times {10}^{-19}}{3\times {10}^8}=1.6\times {10}^{-21}kgm{s}^{-1}$